Iron-containing mineral sintered ore sample, preparation method thereof and mineral phase generation performance evaluation method

Abstract

The invention discloses an iron-containing mineral sintered ore sample, a preparation method thereof and a mineral phase generation performance evaluation method. The preparation method comprises the following steps: providing an iron-containing raw material to be detected, a quicklime powder sample, a dolomite powder sample and a target ore blending structure; according to the adhesion powder proportion of the target ore blending structure, calculating the proportion of the iron-containing raw material to be detected, the quicklime powder sample and the dolomite powder sample in the target ore blending powder, and preparing and mixing according to the proportion to obtain the target ore blending powder; and the target ore blending powder is subjected to pressing treatment and sintering treatment in sequence, and an iron-containing mineral sintered ore sample is obtained. The preparation method disclosed by the invention can be closer to the conditions of sintering the adhesion powder to generate the mineral phase in actual production, the actual participation factors in the production can be more comprehensively covered, and the mineral phase generation performance of the iron ore powder can be more accurately judged.

Description

Technical Field

[0001] This application belongs to the field of iron ore smelting technology, and in particular relates to an iron-bearing mineral sinter sample, its preparation method, and a method for evaluating the mineral phase formation performance. Background Technology

[0002] Existing methods for testing the sintering performance of iron-containing raw materials only include methods for detecting calcium ferrite formation. Firstly, these methods grind the iron ore before testing, neglecting the influence of the original particle size distribution of the iron ore on the sintering process. Grinding the iron ore increases the contact area with CaO and MgO fluxes (such as quicklime powder and dolomite powder), affecting the composition and structure of the sinter. Secondly, iron ore itself contains CaO, MgO, and SiO2, so the amount of quicklime added varies depending on the type of ore. The flux ratio in actual production is determined by the composition of all the mixed materials and the sinter. The particle size distribution and composition of the raw materials affect the flux ratio in the melting zone. The existing binary basicity method has limitations in accurately reflecting the flux ratio in the melting zone during actual industrial production. Thirdly, the calcium ferrite formation capability test only considers binary basicity, i.e., the reaction between CaO flux and iron ore powder. However, MgO flux has a significant impact on the formation of mineral phases, and the mineral phase composition of the sinter is a key factor affecting its performance. Summary of the Invention

[0003] This application provides an iron-bearing mineral sinter sample, its preparation method, and an evaluation method for mineral phase formation performance. This method can more closely approximate the conditions for mineral phase formation in actual production sintering of adhering powder, more comprehensively cover the actual factors involved in production, and more accurately determine the mineral phase formation performance of iron ore powder.

[0004] In a first aspect, embodiments of this application provide a method for preparing an iron-bearing mineral sinter sample, comprising: providing an iron-bearing raw material to be tested, quicklime powder, dolomite powder, and a target ore blending structure; calculating the proportions of the iron-bearing raw material to be tested, quicklime powder, and dolomite powder in the target ore blending powder according to the proportion of adhering powder in the target ore blending structure, and mixing them in the proportions to obtain the target ore blending powder; and subjecting the target ore blending powder to pressing and sintering processes in sequence to obtain an iron-bearing mineral sinter sample.

[0005] In some specific embodiments, based on the total mass of the quicklime powder sample, the quicklime powder sample includes 80%-85% CaO, 1%-2% SiO2 and 1.5%-2.0% MgO, and the particle size of the quicklime powder sample is of full particle size.

[0006] In some specific embodiments, based on the total mass of the dolomite powder sample, the dolomite powder sample includes 30%-35% CaO and 15%-25% MgO, and the particle size of the dolomite powder sample is of full particle size.

[0007] In some specific embodiments, the step of calculating the proportions of the iron-containing raw material to be tested, quicklime powder, and dolomite powder in the target ore blending powder based on the proportion of the binder powder in the target ore blending structure, and then mixing them according to the proportions to obtain the target ore blending powder includes: determining the proportion of the binder powder of the iron-containing raw material to be tested based on the proportion of the binder powder in the target iron-containing ore blending structure; determining the ratio of quicklime and dolomite in the target ore blending powder based on the proportion of the binder powder in the target iron-containing ore blending structure, the binary basicity and magnesium content of the target iron-containing ore blending structure, the proportion of quicklime and the proportion of dolomite in the target iron-containing ore blending structure, and then mixing them according to the proportions to obtain the target ore blending powder. Optionally, the binary basicity of the target iron-containing ore blending structure is 1.85-2.05, and the magnesium content of the target iron-containing ore blending structure is 1.7%-1.9%.

[0008] In some specific embodiments, the steps of calculating the proportions of the iron-containing raw material to be tested, quicklime powder, and dolomite powder in the target ore powder according to the proportion of the adhesive powder in the target ore powder structure, and mixing them according to the proportions to obtain the target ore powder include: adding water to a certain amount of quicklime to digest hydrated lime and then mixing it with a certain amount of the iron-containing raw material to be tested and dolomite powder to obtain the target ore powder.

[0009] In some specific embodiments, the steps of obtaining iron-bearing mineral sinter samples by sequentially pressing and sintering the target ore powder include: pressing the target ore powder under constant pressure of 400N-800N for 3min-5min to obtain a cake sample; and sintering the cake sample at constant temperature of 1250℃-1280℃ for 3min-5min to obtain iron-bearing mineral sinter samples.

[0010] Secondly, this application provides an iron-bearing mineral sinter sample, which is prepared by the preparation method of the first aspect.

[0011] Thirdly, embodiments of this application provide a method for evaluating the mineral phase formation performance of iron-bearing minerals. The evaluation method includes: providing an iron-bearing mineral sinter sample prepared by the preparation method of the first aspect; preparing the iron-bearing mineral sinter sample into a test slide; and performing microstructural analysis on the test slide to evaluate the calcium ferrite formation ability of the iron-bearing mineral.

[0012] In some specific embodiments, the steps of preparing the iron-bearing mineral sinter sample into a test slide include: after mounting the iron-bearing mineral sinter sample, rough polishing is performed using 180-grit sandpaper to create a relatively complete observation surface, followed by rough polishing using 400-grit sandpaper to make the observation surface basically flat; then fine polishing is performed using 800-1200-grit sandpaper for 10-20 minutes each to obtain the polished sample; the polished sample is then polished by adding water and Al2O3 suspension as a medium, and polishing for 5-10 minutes to make the surface of the slide bright, thus obtaining the test slide.

[0013] In some specific embodiments, the steps of performing microstructural analysis on the test slide to evaluate the calcium ferrite formation ability of iron-bearing minerals include: observing the pore structure and crack distribution of sintered iron-bearing minerals at a magnification of 50x-100x, where the size, proportion, and distribution of pores and cracks have a significant impact on the strength, reduction performance, and pulverization performance of the sinter; confirming the mineral composition and its embedding characteristics by analyzing the chemical composition, mineral reflection color, and distribution area of ​​the iron-bearing mineral sinter sample at a magnification of 200x-500x; and evaluating the mineral phase formation performance of iron-bearing minerals based on the mineral reflection color, morphological characteristics, and distribution area of ​​each mineral phase.

[0014] This application has at least the following beneficial effects: The iron-bearing mineral sinter samples, their preparation methods, and the evaluation methods for mineral phase formation performance provided in this application use single-mineral binder powder as raw material and quicklime and dolomite used in production as flux. The actual sintering conditions of the binder powder in actual production are simulated based on the binary basicity of the actual ore blending structure and the magnesium content of the sinter. This method is closer to the raw material and flux conditions used in production and closer to the actual sintering industry. It reduces the limitations of raw material particle size and binary basicity in traditional methods, reduces the artificial increase of the contact area between iron ore powder and flux, and more comprehensively covers the factors affecting the mineral phase composition in sintering production, accurately judging the mineral phase formation performance of iron-bearing raw materials. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a temperature rise curve of the micro sintering high-temperature reactor in the embodiments and comparative examples of this application.

[0017] Figure 2 This is a mineral phase composition diagram of a sintered sample from Example 1 of this application.

[0018] Figure 3 This is a mineral phase composition diagram of another sintered sample from Embodiment 1 of this application.

[0019] Figure 4 This is a mineral phase composition diagram of another sintered sample from Embodiment 1 of this application.

[0020] Figure 5 This is a mineral phase composition diagram of a sintered sample from Embodiment 2 of this application.

[0021] Figure 6This is a mineral phase composition diagram of another sintered sample from Embodiment 2 of this application.

[0022] Figure 7 This is a mineral phase composition diagram of another sintered sample from Embodiment 2 of this application.

[0023] Figure 8 This is a mineral phase composition diagram of a sintered sample from Example 3 of this application.

[0024] Figure 9 This is a mineral phase composition diagram of another sintered sample from Embodiment 3 of this application.

[0025] Figure 10 This is a mineral phase composition diagram of another sintered sample from Example 3 of this application.

[0026] Figure 11 This is a mineral phase composition diagram of a sintered sample of Comparative Example 1 of this application.

[0027] Figure 12 This is a mineral phase composition diagram of another sintered sample of Comparative Example 1 of this application.

[0028] Figure 13 This is a mineral phase composition diagram of another sintered sample of Comparative Example 1 of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] As used in this application, the terms “comprising,” “containing,” and “including” are used in their open, non-restrictive sense.

[0031] Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format in this document. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only the numerical values ​​explicitly specified as range limits, but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified.

[0032] In the detailed description and claims, a list of items connected by the terms "one or more of," "one or more of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A or B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, or C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0033] During the preparation of sintered iron ore powder, a series of reactions occur, resulting in the development, growth, crystallization, and rearrangement of various minerals to form various solid and liquid phases. Different iron ore powders produce different microstructures under different conditions, and the complex microstructure determines the quality of the ore formation. To accurately evaluate the quality of the solid and liquid phases of sintered iron ore powder and improve its microstructure, it is necessary to study the microstructure of sintered iron ore powder. Currently, the standard for judging the sintering performance of iron ore powder based on the microstructure of the sintered iron ore powder is the calcium ferrite formed after the reaction of iron ore powder with CaO.

[0034] The commonly used standard for testing the calcium ferrite formation capacity of iron ore powder is to grind the iron ore powder, mix it with CaO at a fixed binary basicity, press it into briquettes, and sinter it according to a specific sintering regime. The resulting sinter is then inlaid and polished to obtain a clear observation surface, and the mineral phase formation performance is observed under a microscope. Existing methods for testing calcium ferrite formation capacity involve grinding the iron ore finely before conducting experiments, neglecting the influence of the original particle size distribution of the iron ore on the sintering process. Fine grinding increases the contact area with CaO flux (such as quicklime powder). Experiments show that for the same ore, the finer the particle size, the easier it is to form a liquid phase, which lowers the liquid phase formation temperature and affects the composition and structure of the sinter. On the other hand, iron ore itself contains CaO and SiO2, so the amount of quicklime added varies depending on the type of ore. The flux ratio in actual production is determined by the composition of all the mixed materials and sinter. The particle size distribution and composition of the raw materials affect the flux ratio in the molten zone. Using the binary basicity method has limited applicability to the flux ratio in the molten zone during actual industrial production, and its applicability to the actual microstructure formed by the ore type in industrial production is also limited. Third, the calcium ferrite formation capacity test only considers binary basicity, i.e., the reaction between CaO flux and iron ore powder. However, in reality, MgO flux has a significant impact on the formation of mineral phases, and the mineral phase composition of the sinter is a key factor affecting the performance of the sinter.

[0035] Based on the above problems, this application provides an iron-bearing mineral sinter sample and its preparation method, as well as an evaluation method for calcium ferrite formation capacity. This method can effectively reduce the impact of fixed binary basicity and the differences in the composition of individual iron ore powders on sinter. At the same time, it comprehensively considers other factors involved in mineralization in actual production, thereby improving the evaluation accuracy of the sintering and mineralization performance of iron-bearing minerals.

[0036] The method for preparing iron-bearing mineral sinter samples provided in this application includes the following steps: S100 to S300.

[0037] S100 provides the iron-containing raw materials to be tested, quicklime powder samples, dolomite powder samples, and the target ore blending structure.

[0038] S200: Based on the proportion of adhesive powder in the target ore blending structure, the proportions of the iron-containing raw material to be tested, quicklime powder, and dolomite powder in the target ore blending powder are calculated, and the powder is mixed in proportion to obtain the target ore blending powder.

[0039] S300, the target ore powder is successively pressed and sintered to obtain iron-bearing mineral sinter samples.

[0040] The method for preparing iron-bearing mineral sinter samples provided in this application uses single-mineral binder powder as raw material and quicklime and dolomite used in production as flux. It simulates the actual sintering conditions of binder powder in production based on the binary basicity and magnesium content of the sinter according to the actual ore blending structure. This method is closer to the raw material and flux conditions used in production and closer to the actual sintering industry. It reduces the limitations of raw material particle size and fixed binary basicity in traditional methods, reduces the artificial increase of contact area between iron ore powder and flux, and comprehensively considers the flux involved in ore formation, so that the sintering phase formation performance of iron ore powder is more in line with the actual raw material.

[0041] It should be noted that the adhesive powder mentioned in this application refers to particles with a particle size of <0.5mm. The adhesive powder forms an adhesive film by adsorbing water on its surface, which coats coarse particles with a particle size of >0.5mm, promotes mechanical interlocking and hydrogen bonding between particles, and improves the strength and roundness of green pellets.

[0042] In some specific embodiments, based on the total mass of the quicklime powder sample, the quicklime powder sample includes 80%-85% CaO, 1%-2% SiO2 and 1.5%-2.0% MgO, and the particle size of the quicklime powder sample is of full particle size.

[0043] As an example, based on the total mass of the quicklime powder sample, the mass percentage of CaO in the quicklime powder sample can be 80%, 81%, 82%, 83%, 84%, 85%, or any range of the above values. The mass percentage of SiO2 in the quicklime powder sample can be 1%, 1.2%, 1.5%, 1.8%, 2%, or any range of the above values. The mass percentage of MgO in the quicklime powder sample can be 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, or any range of the above values.

[0044] In some specific embodiments, based on the total mass of the dolomite powder sample, the dolomite powder sample includes 30%-35% CaO and 15%-25% MgO, and the particle size of the dolomite powder sample is of full particle size.

[0045] As an example, based on the total mass of the dolomite powder, the mass percentage of CaO in the dolomite powder can be 30%, 31%, 32%, 33%, 34%, 35%, or any range of the above values. The mass percentage of MgO in the dolomite powder can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or any range of the above values.

[0046] In some specific embodiments, S200, based on the proportion of adhering powder in the target ore blending structure, the proportions of the iron-containing raw material to be tested, quicklime powder, and dolomite powder in the target ore blending powder are calculated, and the target ore blending powder is prepared and mixed according to the proportions, including: S210, Determine the proportion of adhesive powder in the iron-bearing raw material to be tested based on the proportion of adhesive powder in the target iron-bearing ore blending structure; S220, based on the remaining proportion of adsorbed powder in the target iron-bearing ore blend, the binary basicity and magnesium content of the target iron-bearing ore blend, the proportion of quicklime and the proportion of dolomite, the ratio of quicklime and dolomite in the target ore blend powder is determined, and the target ore blend powder is prepared and mixed according to the ratio.

[0047] In some specific embodiments, the binary basicity of the target iron-bearing ore blend structure is 1.85-2.05.

[0048] As an example, the binary basicity of the target iron-bearing ore blend structure can be 1.85, 1.88, 1.9, 1.92, 1.95, 1.98, 2, 2.02, 2.05, or any range of the above values.

[0049] In some specific embodiments, the mass percentage of magnesium in the target iron-bearing ore structure is 1.7%-1.9%.

[0050] As an example, the mass percentage of magnesium in the target iron-bearing ore structure can be 1.7%, 1.72%, 1.75%, 1.78%, 1.8%, 1.82%, 1.85%, 1.88%, 1.9%, or any range of the above values.

[0051] In the above specific embodiments, this application further adjusts the effect of MgO on the formation of calcium ferrite during sintering by adjusting the amount of dolomite added. The Mg content in the sintered iron-bearing mineral samples can be adjusted according to the MgO content in different iron ores, making the samples more closely resemble actual application scenarios.

[0052] In some specific embodiments, S200, based on the proportion of adhering powder in the target ore blending structure, the proportions of the iron-containing raw material to be tested, quicklime powder, and dolomite powder in the target ore blending powder are calculated, and the target ore blending powder is prepared and mixed according to the proportions, including: S230 involves mixing a proportion of quicklime with water to digest hydrated lime into slaked lime, and then mixing this mixture with a proportion of the iron-containing raw material to be tested and a dolomite powder sample to obtain the target ore powder.

[0053] In some specific embodiments, S300, the target ore powder is sequentially subjected to pressing and sintering to obtain an iron-bearing mineral sinter sample, including: S310, target ore powder is subjected to constant pressure of 400N-800N for 3-5 minutes to obtain a cake sample.

[0054] S320, the cake sample is sintered at a constant temperature of 1250℃-1280℃ for 3-5 minutes to obtain iron-bearing mineral sintered ore sample.

[0055] This application provides an iron-bearing mineral sinter sample, which is prepared by the above-described preparation method.

[0056] This application provides a method for evaluating the mineral phase formation performance of iron-bearing minerals, the evaluation method including steps S400 to S600.

[0057] S400 provides an iron-bearing mineral sinter sample prepared by the above preparation method.

[0058] S500 prepares iron-bearing mineral sinter samples into optical sheets for testing.

[0059] The S600 is used to perform microstructural analysis on the test slides to evaluate the mineral phase formation properties of iron-bearing minerals.

[0060] The evaluation method provided in this application is easy to operate, uses simple equipment, has low testing costs, and is highly accurate. It can evaluate and judge the mineral phase formation performance of iron ore powder under actual sintering production conditions and is suitable for practical applications.

[0061] In some specific embodiments, S500, preparing the iron-bearing mineral sinter sample into a test optical film includes: S510: After mounting the iron-bearing sintered mineral sample, use 180-grit sandpaper for rough polishing to create the observation surface, then use 400-grit sandpaper for rough polishing to make the observation surface basically flat; then use 800-1200-grit sandpaper for fine polishing for 10-20 minutes each to obtain the polished sample. S520: Polish the ground sample by adding water and Al2O3 suspension as a medium and polishing for 5-10 minutes to make the surface of the light film bright, thus obtaining the light film to be tested.

[0062] As an example, in step 520, long-pile polishing cloth and short-pile polishing cloth can be used to polish the ground sample in sequence.

[0063] In some specific embodiments, S600, performing microstructural analysis on the test film to evaluate the calcium ferrite formation capacity of iron-containing minerals includes: S610, under magnification of 50x to 100x, observe the pore structure and crack distribution of iron-bearing mineral sinter samples. The size, proportion and distribution of pores and cracks have a significant impact on the strength, reduction performance and pulverization performance of sinter.

[0064] S620, under magnification of 200x to 500x, confirms the mineral composition and its embedding characteristics by analyzing the chemical composition, mineral reflection color, and distribution area of ​​iron-bearing sintered ore samples.

[0065] S630: Evaluate the mineral phase formation performance of iron-bearing minerals based on the mineral reflection color, morphological characteristics, and distribution area of ​​each phase.

[0066] Example The following embodiments describe the disclosure of this application in more detail. These embodiments are for illustrative purposes only, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0067] Example 1 In this embodiment, the iron-containing raw material to be tested is a high-silica concentrate. The quicklime powder sample includes 85% CaO, 3% SiO2, and 1% MgO, and the quicklime powder sample is of full particle size. The dolomite powder sample includes 31% CaO, 1% SiO2, and 20% MgO, and the dolomite powder sample is of full particle size.

[0068] The iron-containing raw material to be tested was dried at 110℃ for 2 hours. A 200g sample was taken and sieved through a 0.5mm standard sieve to obtain the -0.5mm particle size, which was then dried and weighed. The proportion of the -0.5mm particle size adhering powder in the iron-containing raw material was calculated. Three parallel experiments were conducted, with an error not exceeding 0.5%, and the average of the three experiments was taken. The -0.5mm particle size sample was retained. Specific experimental values ​​are shown in Table 1.

[0069] Table 1. Experimental data on the proportion of adhering powder in the -0.5mm particle size of the iron-containing raw material to be tested. Based on the target ore blending structure, the proportion of the -0.5mm particle size adhering powder of the iron-containing raw material to be tested is substituted into the target ore blending structure, and the proportion of the adhering powder of the iron-containing raw material to be tested is obtained by weighted calculation. Based on the binary basicity, magnesium content of sintered ore and the proportion of remaining adhering powder of the target ore blending structure, the proportions of quicklime and dolomite are substituted into the blending ratio, and the proportion of adhering powder quicklime and dolomite is obtained by weighted calculation.

[0070] Specifically, referring to Table 2, the proportion of -0.5mm particle size adhering powder of the iron-containing raw material to be tested obtained in Table 1 is approximately 95%. This proportion is then substituted into the adhering powder ratio of the iron ore powder to be tested in Table 2 to calculate the adhering powder weight of the iron ore powder to be tested and other iron ore powders.

[0071] Table 2 Target Ore Mixture Structure Adhesive Powder Distribution Table Based on the weight of the binder powder in the iron-containing raw materials, the proportion of binder powder in the iron-containing raw materials is estimated to be 41.18%.

[0072] Prepare a homogenized material according to the target ore blending structure shown in Table 2, and substitute it into the obtained value of 41.18% of the binder powder in the iron-containing raw material.

[0073] The ratio of quicklime to dolomite in the mixture is calculated accordingly, as shown in Table 3.

[0074] Table 3. Distribution of Adhesive Powder in Mixed Ore Blending The calculated ratios are: quicklime = 0.077 / 0.6465 * 100% = 11.91% and dolomite = 0.057 / 0.6465 * 100% = 8.82%.

[0075] Take 1.5g of the iron-containing mineral to be tested, and mix it with quicklime at a ratio of 1:1. Calculate the amount of quicklime (1.5g * quicklime ratio / (1 - quicklime ratio)) according to the quicklime ratio calculated above. Weigh 0.2028g of quicklime sample. Also calculate the amount of dolomite (1.5g * dolomite ratio / (1 - dolomite ratio)) and weigh 0.1451g of dolomite sample. After the quicklime is hydrated with water to form slaked lime, mix it with dolomite and the iron ore powder to be tested. Press the mixture into a cake shape using an 8mm abrasive mold at a pressure of 400N for 4 minutes.

[0076] Using a micro sintering high-temperature reactor, the temperature was raised to 1280℃ in 10 minutes, held for 5 minutes, and then cooled to below 1000℃ in 4 minutes. The settings were as follows: Figure 1 The temperature curve is shown. The sample was placed in the heating furnace according to the set frequency and temperature curve, and heated at 1280℃ for 5 minutes.

[0077] The cooled mineral phase sample is placed in a hot mounting machine, metallographic mounting material is added, and it is heated under pressure at 200℃ for 10 minutes to prepare the mineral phase sample.

[0078] The prepared mineral phase sample was coarsely polished with 180-400 grit sandpaper to smooth the sample; then finely polished with 800-1200 grit sandpaper to remove any marks from the surface of the polished sheet.

[0079] The mineral phase sample was polished using long-pile and short-pile polishing cloths. Water and Al2O3 suspension were added as a medium. Polishing was carried out for 5-10 minutes to make the surface of the polished sheet bright. The sample was then rinsed with clean water and dried in an electronic drying oven.

[0080] The mineral phase composition of the sample was observed under a microscope, and the results are as follows: Figure 2 , Figure 3 and Figure 4 As shown, in the mineral phase structure of the embodiment, calcium ferrite has a good production capacity and good crystallization, mainly in the form of needle-like, dendritic, and molten forms. The hematite structure is mainly massive, well cemented with calcium ferrite, and contains a small amount of skeletal crystals and porous hematite after sintering of limonite.

[0081] Example 2 The difference between Example 2 and Example 1 is that the iron-containing raw material to be tested in this example is a low-silicon coarse-grained limonite with an adhering powder ratio of 27.03%.

[0082] The quicklime powder sample contains 85% CaO, 3% SiO2, and 1% MgO, and is taken from all particle sizes. The dolomite powder sample contains 31% CaO, 1% SiO2, and 20% MgO, and is taken from all particle sizes.

[0083] The iron-containing raw material to be tested was dried at 110℃ for 2 hours. A 200g sample was taken and sieved through a 0.5mm standard sieve to obtain the -0.5mm particle size, which was then dried and weighed. The proportion of the -0.5mm particle size adhering powder in the iron-containing raw material was calculated. Three parallel experiments were conducted, with an error not exceeding 0.5%, and the average of the three experiments was taken. The -0.5mm particle size sample was retained. Specific experimental values ​​are shown in Table 4.

[0084] Table 4 Experimental data on the proportion of adhering powder in the -0.5mm particle size of the iron-containing raw material to be tested. Based on the target ore blending structure, the proportion of the -0.5mm particle size adhering powder of the iron-containing raw material to be tested is substituted into the target ore blending structure, and the proportion of the adhering powder of the iron-containing raw material to be tested is obtained by weighted calculation. Based on the binary basicity, magnesium content of sintered ore and the proportion of remaining adhering powder of the target ore blending structure, the proportions of quicklime and dolomite are substituted into the blending ratio, and the proportion of adhering powder quicklime and dolomite is obtained by weighted calculation.

[0085] Specifically, referring to Table 5, the proportion of -0.5mm particle size adhering powder of the iron-containing raw material to be tested obtained in Table 4 is approximately 95%. This proportion is then substituted into the proportion of adhering powder of the iron ore powder to be tested in Table 4 to calculate the adhering powder weight of the iron ore powder to be tested and other iron ore powders.

[0086] Table 5 Target Ore Blending Structure Adhesive Powder Distribution Table Based on the weight of the binder powder in the iron-containing raw materials, the proportion of binder powder in the iron-containing raw materials is estimated to be 41.18%.

[0087] Prepare a homogenized material according to the target ore blending structure shown in Table 5, and substitute it into the obtained value of 41.18% of the binder powder in the iron-containing raw material.

[0088] The ratio of quicklime to dolomite in the mixture is calculated accordingly, as shown in Table 6.

[0089] Table 6. Distribution of Adhesive Powder in Mixed Ore Blending The calculated ratios are: quicklime = 0.077 / 0.6465 * 100% = 11.91% and dolomite = 0.057 / 0.6465 * 100% = 8.82%.

[0090] Take 1.5g of the iron-containing mineral to be tested, and mix it with quicklime at a ratio of 1:1. Calculate the amount of quicklime (1.5g * quicklime ratio / (1 - quicklime ratio)) according to the quicklime ratio calculated above. Weigh 0.2028g of quicklime sample. Also calculate the amount of dolomite (1.5g * dolomite ratio / (1 - dolomite ratio)) and weigh 0.1451g of dolomite sample. After the quicklime is hydrated with water to form slaked lime, mix it with dolomite and the iron ore powder to be tested. Press the mixture into a cake shape using an 8mm abrasive mold at a pressure of 400N for 4 minutes.

[0091] Using a micro sintering high-temperature reactor, the temperature was raised to 1280℃ in 10 minutes, held for 5 minutes, and then cooled to below 1000℃ in 4 minutes. The settings were as follows: Figure 1 The temperature curve is shown. The sample was placed in the heating furnace according to the set frequency and temperature curve, and heated at 1280℃ for 5 minutes.

[0092] The cooled mineral phase sample is placed in a hot mounting machine, metallographic mounting material is added, and it is heated under pressure at 200℃ for 10 minutes to prepare the mineral phase sample.

[0093] The prepared mineral phase sample was coarsely polished with 180-400 grit sandpaper to smooth the sample; then finely polished with 800-1200 grit sandpaper to remove any marks from the surface of the polished sheet.

[0094] The mineral phase sample was polished using long-pile and short-pile polishing cloths. Water and Al2O3 suspension were added as a medium. Polishing was carried out for 5-10 minutes to make the surface of the polished sheet bright. The sample was then rinsed with clean water and dried in an electronic drying oven.

[0095] The resulting mineral phase composition is as follows Figure 5 , Figure 6 and Figure 7 As shown, the calcium ferrite formation is relatively good, and it is intertwined with hematite through melting. There is a small amount of skeletal hematite and a small amount of magnesium ferrite. There are few cavities, but many cracks.

[0096] Example 3 The difference between Example 3 and Example 1 is that the iron-containing raw material to be tested in this example is a coarse-grained hematite with medium silica, and the proportion of adhering powder is 9.74%.

[0097] The quicklime powder sample contains 85% CaO, 3% SiO2, and 1% MgO, and is taken from all particle sizes. The dolomite powder sample contains 31% CaO, 1% SiO2, and 20% MgO, and is taken from all particle sizes.

[0098] The iron-containing raw material to be tested was dried at 110℃ for 2 hours. A 200g sample was taken and sieved through a 0.5mm standard sieve to obtain the -0.5mm particle size, which was then dried and weighed. The proportion of the -0.5mm particle size adhering powder in the iron-containing raw material was calculated. Three parallel experiments were conducted, with an error not exceeding 0.5%, and the average of the three experiments was taken. The -0.5mm particle size sample was retained. Specific experimental values ​​are shown in Table 7.

[0099] Table 7 Experimental data on the proportion of adhering powder in the -0.5mm particle size of the iron-containing raw material to be tested. Based on the target ore blending structure, the proportion of the -0.5mm particle size adhering powder of the iron-containing raw material to be tested is substituted into the target ore blending structure, and the proportion of the adhering powder of the iron-containing raw material to be tested is obtained by weighted calculation. Based on the binary basicity, magnesium content of sintered ore and the proportion of remaining adhering powder of the target ore blending structure, the proportions of quicklime and dolomite are substituted into the blending ratio, and the proportion of adhering powder quicklime and dolomite is obtained by weighted calculation.

[0100] Specifically, referring to Table 8, the proportion of -0.5mm particle size adhering powder of the iron-containing raw material to be tested obtained in Table 7 is approximately 95%, which is then substituted into the proportion of adhering powder of the iron ore powder to be tested in Table 8 to calculate the weight of adhering powder of the iron ore powder to be tested and other iron ore powders.

[0101] Table 8 Target Ore Mixture Structure Adhesive Powder Distribution Table Based on the weight of the binder powder in the iron-containing raw materials, the proportion of binder powder in the iron-containing raw materials is estimated to be 41.18%.

[0102] Prepare a homogenized material according to the target ore blending structure shown in Table 8, and substitute it into the obtained value of 41.18% of the binder powder in the iron-containing raw material.

[0103] The ratio of quicklime to dolomite in the mixture is calculated accordingly, as shown in Table 9.

[0104] Table 9. Distribution of Adhesive Powder in Mixed Ore Blending The calculated ratios are: quicklime = 0.077 / 0.6465 * 100% = 11.91% and dolomite = 0.057 / 0.6465 * 100% = 8.82%.

[0105] Take 1.5g of the iron-containing mineral to be tested, and mix it with quicklime at a ratio of 1:1. Calculate the amount of quicklime (1.5g * quicklime ratio / (1 - quicklime ratio)) according to the quicklime ratio calculated above. Weigh 0.2028g of quicklime sample. Also calculate the amount of dolomite (1.5g * dolomite ratio / (1 - dolomite ratio)) and weigh 0.1451g of dolomite sample. After the quicklime is hydrated with water to form slaked lime, mix it with dolomite and the iron ore powder to be tested. Press the mixture into a cake shape using an 8mm abrasive mold at a pressure of 400N for 4 minutes.

[0106] Using a micro sintering high-temperature reactor, the temperature was raised to 1280℃ in 10 minutes, held for 5 minutes, and then cooled to below 1000℃ in 4 minutes. The settings were as follows: Figure 1 The temperature curve is shown. The sample was placed in the heating furnace according to the set frequency and temperature curve, and heated at 1280℃ for 5 minutes.

[0107] The cooled mineral phase sample is placed in a hot mounting machine, metallographic mounting material is added, and it is heated under pressure at 200℃ for 10 minutes to prepare the mineral phase sample.

[0108] The prepared mineral phase sample was coarsely polished with 180-400 grit sandpaper to smooth the sample; then finely polished with 800-1200 grit sandpaper to remove any marks from the surface of the polished sheet.

[0109] The mineral phase sample was polished using long-pile and short-pile polishing cloths. Water and Al2O3 suspension were added as a medium. Polishing was carried out for 5-10 minutes to make the surface of the polished sheet bright. The sample was then rinsed with clean water and dried in an electronic drying oven.

[0110] The resulting mineral phase composition is as follows Figure 8 , Figure 9 and Figure 10 As shown, the calcium ferrite content is relatively high, with some of it melting with hematite and others forming needle-like and dendritic shapes. The magnesium ferrite content is also relatively high, with small and few cavities overall.

[0111] Comparative Example 1 The iron-containing raw material to be tested in Example 1 was dried at 110°C for 2 hours. 200g of the dried sample was taken, and the -0.5mm particle size was obtained by sieving through a 0.5mm standard sieve and then dried for later use.

[0112] Given that the iron-containing minerals contain 1.57% silicon and 0.52% calcium, and the quicklime contains 85% calcium and 1.0% silicon, the mass of the quicklime is calculated to be 0.0742g using the formula (iron-containing mineral calcium content * iron-containing mineral mass + quicklime calcium content * quicklime mass) / (iron-containing mineral silicon content * iron-containing mineral mass + quicklime silicon content * quicklime mass) = 3.

[0113] Take 1.5g of the iron-containing mineral to be tested, weigh 0.0742g of quicklime sample, add water to digest the slaked lime and mix it with the iron ore powder to be tested. Press the mixture into a cake shape using an 8mm abrasive, apply a pressure of 400N and maintain the pressure for 4 minutes.

[0114] Using a micro sintering high-temperature reactor, the temperature was raised to 1280℃ in 10 minutes, held for 5 minutes, and then cooled to below 1000℃ in 4 minutes. The settings were as follows: Figure 1 The temperature curve shown; the sample was sent into the heating furnace according to the set frequency and temperature curve, and kept at 1280℃ for 5 minutes.

[0115] The cooled mineral phase sample is placed in a hot mounting machine, metallographic mounting material is added, and it is heated under pressure at 200℃ for 10 minutes to prepare the mineral phase sample.

[0116] The prepared mineral phase sample was coarsely polished with 180-400 grit sandpaper to smooth the sample; then finely polished with 800-1200 grit sandpaper to remove any marks from the surface of the polished sheet.

[0117] The mineral phase sample was polished using long-pile and short-pile polishing cloths. Water and Al2O3 suspension were added as a medium. Polishing was carried out for 5-10 minutes to make the surface of the polished sheet bright. The sample was then rinsed with clean water and dried in an electronic drying oven.

[0118] The mineral phase composition of the sample was observed under a microscope, and the results are as follows: Figure 11 , Figure 12 and Figure 13 As shown, in Comparative Example 1, the mineral phase structure exhibits good calcium ferrite formation ability, presenting as molten and acicular structures, with abundant massive and molten hematite structures, and obvious reniform and spongy hematite formations after sintering of limonite. The low calcium oxide content resulted in shrinkage during sintering.

[0119] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing an iron-bearing mineral sinter sample, characterized in that, include: Provide the iron-containing raw materials to be tested, quicklime powder samples, dolomite powder samples, and the target ore blending structure; Based on the proportion of adsorbed powder in the target ore blending structure, the proportions of the iron-containing raw material to be tested, quicklime powder, and dolomite powder in the target ore blending powder are calculated, and then mixed in proportion to obtain the target ore blending powder. The target ore powder is subjected to pressing and sintering processes in sequence to obtain the iron-bearing mineral sinter sample.

2. The preparation method according to claim 1, characterized in that, Based on the total mass of the quicklime powder sample, the quicklime powder sample comprises 80%-85% CaO, 1%-2% SiO2 and 1.5%-2.0% MgO, and the particle size of the quicklime powder sample is of full particle size range.

3. The preparation method according to claim 1, characterized in that, Based on the total mass of the dolomite powder sample, the dolomite powder sample comprises 30%-35% CaO and 15%-25% MgO, and the particle size of the dolomite powder sample is of full particle size range.

4. The preparation method according to claim 1, characterized in that, The step of calculating the proportions of the iron-containing raw material, quicklime powder, and dolomite powder in the target ore powder based on the adhesive powder proportion of the target ore blending structure, and then mixing them according to the proportions to obtain the target ore powder includes: The proportion of the binder powder in the iron-bearing raw material to be tested is determined based on the proportion of the binder powder in the target iron-bearing ore blending structure. Based on the proportion of adsorbed powder in the target iron-bearing ore blend, the binary basicity and magnesium content of the target iron-bearing ore blend, the proportion of quicklime and the proportion of dolomite, the ratio of quicklime and dolomite in the target ore blend powder is determined, and the target ore blend powder is prepared and mixed according to the ratio. Optionally, the binary basicity of the target iron-bearing ore blend is 1.85-2.05, and the mass percentage content of magnesium in the target iron-bearing ore blend is 1.7%-1.9%.

5. The preparation method according to claim 1, characterized in that, The step of calculating the proportions of the iron-containing raw material to be tested, quicklime powder, and dolomite powder in the target ore powder according to the adhesive powder proportion of the target ore powder structure, and mixing them according to the proportions to obtain the target ore powder includes: adding water to a certain amount of quicklime to digest hydrated lime and then mixing it with a certain amount of the iron-containing raw material to be tested and dolomite powder to obtain the target ore powder.

6. The preparation method according to claim 1, characterized in that, The steps for obtaining the iron-bearing mineral sinter sample by sequentially pressing and sintering the target ore powder include: The target ore powder was subjected to a constant pressure of 400-800N for 3-5 minutes to obtain a cake-shaped sample. The cake-shaped sample was sintered at a constant temperature of 1250℃-1280℃ for 3-5 minutes to obtain the iron-bearing mineral sinter sample.

7. A sample of iron-bearing mineral sinter, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 6.

8. A method for evaluating the mineral phase formation properties of iron-bearing minerals, characterized in that, include: Provide a sintered iron-bearing mineral sample prepared by the preparation method according to any one of claims 1 to 6; The iron-bearing mineral sinter sample was prepared into a test film; Microstructural analysis was performed on the test film to evaluate the mineral phase formation performance of iron-bearing minerals.

9. The evaluation method according to claim 8, characterized in that, The step of preparing the iron-bearing mineral sinter sample into a test optical film includes: After the iron-bearing mineral sinter sample was mounted, it was coarsely polished with 180-grit sandpaper to create the observation surface, and then coarsely polished with 400-grit sandpaper to make the observation surface smooth. Then, it was finely polished with 800-1200-grit sandpaper for 10-20 minutes to obtain the polished sample. The ground sample is polished by adding water and Al2O3 suspension as a medium and polishing for 5-10 minutes to make the surface of the light film bright, thus obtaining the light film to be tested.

10. The evaluation method according to claim 8, characterized in that, The step of performing microstructural analysis on the test slide to evaluate the mineral phase formation performance of iron-bearing minerals includes: Under magnification of 50x-100x, the pore structure and crack distribution of iron-bearing mineral sinter samples were observed. Under magnification of 200x-500x, the mineral composition and its embedding characteristics were confirmed by the chemical composition, mineral reflection color and distribution area of ​​iron-bearing sinter samples. The mineral phase formation performance of iron-bearing minerals is evaluated based on the mineral reflection color, morphological characteristics, and distribution area of ​​each mineral phase.

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